The Core Microscopy and Molecular Histology laboratory provides not only services in routine microscopic techniques such as tissue preparation and analysis by light and electron microscopy for contemporary analytical morphological methods, including immunohistochemistry, immuno-electron microscopy, isotopic and non-isotopic in situ hybridization and digital imaging technology (such as quantitative analysis of microscopic images, and generation of composite images and slides using computer imaging tools). The Microscopy and Molecular Histology Laboratory has also been involved in teaching and training a large number of undergraduate and graduate students, research associates, visiting fellows and residents, while working on different Program Project-related studies. The facility of Core B consists of two physically separate suites of laboratories, with a total of 1,400 square feet (600 square feet + 800 square feet), where separate modules are dedicated to experimental procedures and tissue collection, tissue fixation and processing (dehydration, embedding, resin polymerization, etc.), histology (frozen and paraffin sectioning), ultramicrotomy, cryoultramicrotomy, microscopy (light, fluorescence and electron microscopy), and darkroom work. The personnel of Core B are Laszlo G. Komuves, Ph.D., Director, Dr. Corey Largman, Co-director, and Ms. Angela Kwong, Technician. The Microscopy and Molecular Histology Laboratory has provided not only services (including preparation of fixatives, processing and embedding of tissue samples, and immunohistochemistry or in situ hybridization) for the investigators of the Program Project, but it also has been involved actively in the planning of experiments, and in the analysis and interpretation of the data. The Microscopy and Molecular Histology Laboratory is committed to improving transitional morphological methods; to introduce newly developed techniques; and to devise novel microscopic methods for studying the biology of keratinocytes and the skin. With this background in histologic, electron microscopic, immunohistochemical and in situ hybridization techniques, the Microscopy and Molecular Histology Laboratory will continue to advise and assist investigators of the Program Project with their microscopic and morphological studies, as required. A list of publications that have resulted from these interactions is appended (see List of Publications).